A neuropsychological model for the pre-surgical evaluation of children with focal-onset epilepsy: An integrated approach.

This review explores the complexities of pre-surgical neuropsychological assessment for children with focal-onset epilepsy. A model is proposed outlining a range of factors that potentially influence the neuropsychological formulation. These factors include a developmental, epilepsy, psychological and cognitive dimension, together with family and social context and intrinsic factors. This model is child-centered and recognizes that these factors will be weighted differently for each individual. In some instances the neuropsychological profile might suggest localized and lateralized function, but there are significant limitations to this approach in the context of the contemporary view of epilepsy as a network disorder. This review recognizes that a range of issues impact on neuropsychological function in children with focal-onset epilepsy, including the connectivity between neural systems and the dynamic nature of development. The aim of this review is to provide a neuropsychological framework to enhance and support clinical decision-making in the pre-surgical evaluation of children with focal-onset epilepsy.

Developmental stage affects cognition in children with recently-diagnosed symptomatic focal epilepsy.

This study explored the impact of developmental stage on cognitive function in children with recently-diagnosed epilepsy. In keeping with a neurodevelopmental framework, skills in a critical developmental period were expected to be more vulnerable than those stable at the time of seizure onset. We studied children with early-onset (EO) symptomatic focal epilepsy (onset: 3-5 years; n=18) and compared their performance with that of the group with late-onset (LO) epilepsy (onset: 6-8 years performance of; n=8) on a range of cognitive tasks. Performance of both groups was compared with normative standards. 'Critical' and 'stable' classifications were based on developmental research. Nonparametric analyses revealed that skills in a critical developmental period for the group with EO epilepsy fell below normative standards (Phonological Processing: p=.007, Design Copying: p=.01, Visuomotor Precision:, p=.02) and fell below the performance of the group with LO epilepsy (Design Copying: p=.03, Visuomotor Precision: p=.03). There were no differences between the group with EO epilepsy and the group with LO epilepsy on measures of receptive vocabulary and memory, which were proposed to be in a stable developmental period across both groups. Auditory span, as measured by Word Order, was reduced for both the group with EO epilepsy (p=.02) and the group with LO epilepsy (p=.02) relative to normative standards, but the groups did not differ from each other. These results are consistent with a prolonged period of critical development for this skill. These findings support the notion that skills in a critical phase of development are particularly vulnerable following the onset of symptomatic focal epilepsy in childhood.

Changes in memory function in children and young adults with temporal lobe epilepsy: a follow-up study.

This longitudinal study explored change in memory function from childhood to young adulthood in temporal lobe epilepsy (TLE). The 24 participants (11 left TLE; 13 right TLE) had a mean age of 16.10 years (SD=4.13 years), and 14 had undergone surgery since initial assessment. Contrary to baseline, verbal memory deficits were lateralized (left

The Observer Memory Questionnaire-Parent Form: introducing a new measure of everyday memory for children.

Relatively little research has focused on everyday memory function in childhood, possibly reflecting the limited number of measures available. This study introduces the Observer Memory Questionnaire-Parent Form (OMQ-PF), which assesses parental beliefs about their child's everyday memory. The OMQ-PF and a selection of neuropsychological measures were administered to a cohort of healthy children in Study 1 (n = 376; 5-16 years old) and a temporal lobe epilepsy (TLE) group in Study 2 (n = 44; 6-16 years old). Study 1 found the OMQ-PF had sound internal consistency and was significantly correlated to a learning task. Study 2 found the TLE group was impaired on the OMQ-PF relative to the healthy cohort. Everyday memory ratings were related to a wider range of neuropsychological measures in this group. Findings are encouraging in terms of the properties of the OMQ-PF and suggest further development of the scale is warranted.

The localization and lateralization of memory deficits in children with temporal lobe epilepsy.

PURPOSE: It is often reported that children with temporal lobe epilepsy (TLE) experience nonlateralized memory impairments. However, many of these studies have been exploratory and not based on memory theory. Further, differences between mesial and lateral subgroups have not been adequately examined. This study aimed to discern more specific patterns of memory impairment in children with TLE. METHODS: Forty-three children (5-16 years) with lesional TLE participated. Subjects were categorized in terms of lesion laterality (left, n = 21; right, n = 22) and intratemporal location (mesial, n = 31; lateral, n = 12). Verbal and nonverbal memory tasks were administered that reflected associative, allocentric and recognition paradigms. RESULTS: Facial recognition was poorer in right TLE (p = 0.03). There were no differences between left and right groups on any other memory task, even when comparisons were restricted to cases with mesial involvement. Irrespective of laterality, clear differences were observed between mesial and lateral lesion subgroups (arbitrary associative learning, p = 0.01; complex figure recall, p = 0.03). The lateral lesion subgroup displayed intact memory function relative to normative standards. CONCLUSIONS: Memory is more frequently impaired in children with mesial as opposed to lateral TLE. Tasks with an associative component discriminated between these subgroups, supporting an associative model of hippocampal function. With the exception of facial recognition, memory deficits were not lateralized. Therefore, the nature of memory impairment experienced by children with TLE cannot be extrapolated from adult models.